Automatic maximum-speed governor for electrically-propelled vehicles.



No. 658,l|7. Patented Sept. 18,!900. H. F. PARSHALL. AUTOMATIC MAXIMUM SPEED GOVERNOR FOR ELECTRICALLY PROPELLED VEHICLES.

(Application fi led June 12, 1897.)

WW1. :M.. 1 w Tm t N t if N E Ci \A/ITNESEESI UNITED STATES PATENT OFFICE.

HORACE FIELD rAEsnAL-L, on LONDON, ENGLAND;

AUTOMATIC MAXIMUM-SPEED GOVERNOR FOR ELECTRlCALLY-PROPELLEI) VEHICLES.

SPECIFICATION forming part of Letters Patent No. 658.1 1 '7, dated September 18, 190i).

Application filed June 12, 1897.

To all whom, it may concern:

Be it known that I, HORACE FIELD PAR- SHALL, a citizen of the United States of Amerit-a, residing at 83 Gannon street, in the city of London, England, have invented certain new and useful Improvements in Automatic Speed-Governors, (for which I have obtained a patent in Great Britain, No. 17,666, dated August 10, 1896,) of which the following is a specification.

The object of my invention is to provide an efficient and reliable speed-governor for electric motors.

lWIy improvements are particularly useful in connection with electric motors used to drive vehicles and in that application act to prevent the speed of the vehicles from exceeding a certain predetermined maximum.

My invention contemplates the use of a circuit-breaker capable of opening or modifying the motor-circuit with electrically-operated means for actuating the circuit-breaker in response to changes of speed of the motor.

The nature of my invention will be more specifically pointed out in the following specification and its scope indicated in the annexed claims.

In the drawings attached to this specification, Figure l is a diagrammatic representation of adevit-e embodying my invention, and Fig. 2 is a similar representation of a modilied form.

Referring to Fig. l, A is the shaft of the motor, and Bis a circuit-breaker inserted in series with the motor-armature. This circuitbreaker is here shown constructed in a wellknown manner in accordance with United States Patent No. 558,518 to William B. Potter, though it will be apparent that my invention may be adapted to various other forms of circuit-breakers. In the particular form illustrated the circuit-breaker comprises a switch 15, with an auxiliary switch B in multiple therewith controlled by a handle H through a toggle T. The spring tends continuously to open the circuit first at B and then at B but this tendency is withstood by the action of the latch L, controlled by a spring Z. When the current in the coil 0 rises to a certain predetermined amount, the' latch L is attracted downward and the spring 25 is allowed to withdraw the brush B from the contacts. This serial No. (M01521. (No model.)

causes current to flow through the magnetcoil m m so that by the time the final arc is formed at the contacts B a field exists of sufficient strength to extinguish it.

In carrying out my present invention I provide a tripping-coil O upon the circuit breaker, acting upon the arm atu rep and tending when energized to draw down the latch L and allow the spring if to open the circuit. This coil is connected in series with an auxiliary source of electromotive force, here shown as a battery B, through the stationary contacts b b and the movable contact d. This movable contact is actuated through the lever D by the governor G, which is in some manner run at a speed corresponding to the speed of the motor. If the speed of the motor rises too high, the contact at is closed and the coil 0 is caused to trip the circuit-breaker B.

In the form shown in Fig. 2 I provide as an auxiliary source of electromotive force a generator G, which is mounted on the shaft of the motor A or is in any other way driven at a speed correspondingto the speed of the said motor. This generator is connected directly in series with the auxiliary trippingcoil 0. Whenever the speed of the motor rises above a certain point, the electromotive force generated by the auxiliary generator G becomes sufficient to cause the auxiliary tripping-coil to act, and thus opens the circuit of the motor.

It will be evident that with either of the forms shown it is impossible for the attendant to close the circuit-breaker in such a way that it will remain closed until the speed of the motor or of the apparatus driven by the motor has been reduced to the proper value.

What I claim as new, and desire to secure by Letters Patent of the United States, is-- 1. In combination, a line-circuit, a motor supplied thereby, a circuit-breaker controlling the current flowing to said motor, an auxiliary source of electromotive force,and means for actuating such circuit-breaker by current from the auxiliary source when the motor speed rises too high.

2. In combination, a line-wire, a dynamoelectric machine, a circuit-breaker in the line, an auxiliary dynamo connected to said machine, and a coil on the circuit-breaker in circuit with the auxiliary dynamo.

3. The combination with a dynamo-electric to the speed of the motor rises too high.

5. The combination with a dynamo-electric machine, of a circuit-breaker containing a series coil and an auxiliary coil, and means for causing the auxiliary coil to open the circuit- 7 breaker When the machine departs too much from normal speed. I

In witness whereof I have hereunto set my hand in presence of two Witnesses.

HORACE FIELD PARSIIALL. Witnesses:

W. J. STYPE, W; M. HARRIS. 

